diff --git a/src/address.js b/src/address.js
index 354dda8..9a010dd 100644
--- a/src/address.js
+++ b/src/address.js
@@ -1,7 +1,6 @@
 var base58 = require('./base58')
 var base58check = require('./base58check')
 var convert = require('./convert')
-var error = require('./util').error
 var mainnet = require('./network').mainnet.addressVersion
 
 function Address(bytes, version) {
@@ -25,7 +24,7 @@ function Address(bytes, version) {
       this.version = version || mainnet
     }
     else {
-      error('invalid or unrecognized input')
+      throw new Error('Invalid or unrecognized input')
     }
   }
   else {
diff --git a/src/base58check.js b/src/base58check.js
index ca95048..51c970e 100644
--- a/src/base58check.js
+++ b/src/base58check.js
@@ -1,14 +1,7 @@
 // https://en.bitcoin.it/wiki/Base58Check_encoding
 var assert = require('assert')
 var base58 = require('./base58')
-var crypto = require('crypto')
-
-function sha256(buf) {
-  var hash = crypto.createHash('sha256')
-  hash.update(buf)
-
-  return hash.digest()
-}
+var crypto = require('./crypto')
 
 // Encode a buffer as a base58-check-encoded string
 function encode(buffer, version) {
@@ -19,7 +12,7 @@ function encode(buffer, version) {
   var payload = new Buffer(buffer)
 
   var message = Buffer.concat([version, payload])
-  var checksum = sha256(sha256(message)).slice(0, 4)
+  var checksum = crypto.hash256(message).slice(0, 4)
 
   return base58.encode(Buffer.concat([
     message,
@@ -33,7 +26,7 @@ function decode(string) {
 
   var message = buffer.slice(0, -4)
   var checksum = buffer.slice(-4)
-  var newChecksum = sha256(sha256(message)).slice(0, 4)
+  var newChecksum = crypto.hash256(message).slice(0, 4)
 
   assert.deepEqual(newChecksum, checksum)
 
diff --git a/src/crypto.js b/src/crypto.js
new file mode 100644
index 0000000..64d69e6
--- /dev/null
+++ b/src/crypto.js
@@ -0,0 +1,40 @@
+// Crypto, crypto, where art thou crypto
+var CryptoJS = require('crypto-js')
+var crypto = require('crypto')
+var convert = require('./convert')
+
+function hash160(buffer) {
+  if (!Buffer.isBuffer(buffer)) buffer = new Buffer(buffer) // FIXME: transitionary
+
+  var step1 = sha256(buffer)
+
+  var step2a = convert.bytesToWordArray(step1)
+  var step2b = CryptoJS.RIPEMD160(step2a)
+
+  return new Buffer(convert.wordArrayToBytes(step2b))
+}
+
+function hash256(buffer) {
+  if (!Buffer.isBuffer(buffer)) buffer = new Buffer(buffer) // FIXME: transitionary
+
+  return sha256(sha256(buffer))
+}
+
+function sha1(buffer) {
+  if (!Buffer.isBuffer(buffer)) buffer = new Buffer(buffer) // FIXME: transitionary
+
+  return crypto.createHash('sha1').update(buffer).digest()
+}
+
+function sha256(buffer) {
+  if (!Buffer.isBuffer(buffer)) buffer = new Buffer(buffer) // FIXME: transitionary
+
+  return crypto.createHash('sha256').update(buffer).digest()
+}
+
+module.exports = {
+  sha1: sha1,
+  sha256: sha256,
+  hash160: hash160,
+  hash256: hash256
+}
diff --git a/src/eckey.js b/src/eckey.js
index 190e6de..c5a35bd 100644
--- a/src/eckey.js
+++ b/src/eckey.js
@@ -1,13 +1,13 @@
 var Address = require('./address')
 var assert = require('assert')
-var convert = require('./convert')
 var base58check = require('./base58check')
 var BigInteger = require('./jsbn/jsbn')
+var convert = require('./convert')
+var crypto = require('./crypto')
 var ecdsa = require('./ecdsa')
 var ECPointFp = require('./jsbn/ec').ECPointFp
 var sec = require('./jsbn/sec')
 var Network = require('./network')
-var util = require('./util')
 var ecparams = sec("secp256k1")
 
 // input can be nothing, array of bytes, hex string, or base58 string
@@ -175,7 +175,7 @@ ECPubKey.prototype.toString = ECPubKey.prototype.toHex
 ECPubKey.prototype.getAddress = function(version) {
   version = version || Network.mainnet.addressVersion
 
-  return new Address(util.sha256ripe160(this.toBytes()), version)
+  return new Address(crypto.hash160(this.toBytes()), version)
 }
 
 ECPubKey.prototype.verify = function(hash, sig) {
diff --git a/src/hdwallet.js b/src/hdwallet.js
index a6998b5..6276111 100644
--- a/src/hdwallet.js
+++ b/src/hdwallet.js
@@ -1,30 +1,25 @@
-var convert = require('./convert.js')
-var base58 = require('./base58.js')
+var Address = require('./address')
 var assert = require('assert')
+var base58 = require('./base58')
+var convert = require('./convert')
+var CJS = require('crypto-js')
+var crypto = require('./crypto')
+var ECKey = require('./eckey').ECKey
+var ECPubKey = require('./eckey').ECPubKey
 var format = require('util').format
-var util = require('./util.js')
-var Crypto = require('crypto-js')
-var HmacSHA512 = Crypto.HmacSHA512
-var HMAC= Crypto.algo.HMAC
-var ECKey = require('./eckey.js').ECKey
-var ECPubKey = require('./eckey.js').ECPubKey
-var Address = require('./address.js')
 var Network = require('./network')
 
-var crypto = require('crypto')
+function HmacSHA512(buffer, secret) {
+  var words = convert.bytesToWordArray(buffer)
+  var hash = CJS.HmacSHA512(words, secret)
 
-function sha256(buf) {
-  var hash = crypto.createHash('sha256')
-  hash.update(buf)
-
-  return hash.digest()
+  return convert.wordArrayToBytes(hash)
 }
 
 function HDWallet(seed, network) {
   if (seed === undefined) return;
 
-  var seedWords = convert.bytesToWordArray(seed)
-  var I = convert.wordArrayToBytes(HmacSHA512(seedWords, 'Bitcoin seed'))
+  var I = HmacSHA512(seed, 'Bitcoin seed')
   this.chaincode = I.slice(32)
   this.network = network || 'mainnet'
   if(!Network.hasOwnProperty(this.network)) {
@@ -57,7 +52,7 @@ HDWallet.fromBase58 = function(string) {
 
   var payload = buffer.slice(0, -4)
   var checksum = buffer.slice(-4)
-  var newChecksum = sha256(sha256(payload)).slice(0, 4)
+  var newChecksum = crypto.hash256(payload).slice(0, 4)
 
   assert.deepEqual(newChecksum, checksum)
   assert.equal(payload.length, HDWallet.LENGTH)
@@ -131,15 +126,15 @@ HDWallet.fromBytes = function(input) {
 }
 
 HDWallet.prototype.getIdentifier = function() {
-  return util.sha256ripe160(this.pub.toBytes())
+  return crypto.hash160(this.pub.toBytes())
 }
 
 HDWallet.prototype.getFingerprint = function() {
-  return this.getIdentifier().slice(0, 4)
+  return Array.prototype.slice.call(this.getIdentifier(), 0, 4)
 }
 
 HDWallet.prototype.getAddress = function() {
-  return new Address(util.sha256ripe160(this.pub.toBytes()), this.getKeyVersion())
+  return new Address(crypto.hash160(this.pub.toBytes()), this.getKeyVersion())
 }
 
 HDWallet.prototype.toBytes = function(priv) {
@@ -192,7 +187,7 @@ HDWallet.prototype.toHex = function(priv) {
 
 HDWallet.prototype.toBase58 = function(priv) {
   var buffer = new Buffer(this.toBytes(priv))
-  var checksum = sha256(sha256(buffer)).slice(0, 4)
+  var checksum = crypto.hash256(buffer).slice(0, 4)
 
   return base58.encode(Buffer.concat([
     buffer,
@@ -205,7 +200,7 @@ HDWallet.prototype.derive = function(i) {
     , iBytes = convert.numToBytes(i, 4).reverse()
     , cPar = this.chaincode
     , usePriv = i >= HDWallet.HIGHEST_BIT
-    , SHA512 = Crypto.algo.SHA512
+    , SHA512 = CJS.algo.SHA512
 
   if (usePriv) {
     assert(this.priv, 'Private derive on public key')
@@ -259,7 +254,7 @@ HDWallet.prototype.getKeyVersion = function() {
 HDWallet.prototype.toString = HDWallet.prototype.toBase58
 
 function HmacFromBytesToBytes(hasher, message, key) {
-  var hmac = HMAC.create(hasher, convert.bytesToWordArray(key))
+  var hmac = CJS.algo.HMAC.create(hasher, convert.bytesToWordArray(key))
   hmac.update(convert.bytesToWordArray(message))
   return convert.wordArrayToBytes(hmac.finalize())
 }
diff --git a/src/index.js b/src/index.js
index 52fd4f4..b98749e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -3,6 +3,7 @@ var T = require('./transaction')
 
 module.exports = {
   Address: require('./address'),
+  crypto: require('./crypto'),
   Key: Key.ECKey,
   ECKey: Key.ECKey,
   ECPubKey: Key.ECPubKey,
@@ -12,7 +13,6 @@ module.exports = {
   Script: require('./script'),
   Opcode: require('./opcode'),
   Transaction: T.Transaction,
-  Util: require('./util'),
   TransactionIn: T.TransactionIn,
   TransactionOut: T.TransactionOut,
   ECPointFp: require('./jsbn/ec').ECPointFp,
diff --git a/src/message.js b/src/message.js
index a9ed312..56eee48 100644
--- a/src/message.js
+++ b/src/message.js
@@ -2,9 +2,9 @@
 
 var Address = require('./address')
 var convert = require('./convert')
+var crypto = require('./crypto')
 var ecdsa = require('./ecdsa')
 var ECPubKey = require('./eckey').ECPubKey
-var SHA256 = require('crypto-js/sha256')
 
 // FIXME: magicHash is incompatible with other magic messages
 var magicBytes = convert.stringToBytes('Bitcoin Signed Message:\n')
@@ -19,7 +19,7 @@ function magicHash(message) {
     messageBytes
   )
 
-  return convert.wordArrayToBytes(SHA256(SHA256(convert.bytesToWordArray(buffer))))
+  return crypto.hash256(buffer)
 }
 
 // TODO: parameterize compression instead of using ECKey.compressed
diff --git a/src/script.js b/src/script.js
index 49d78fa..b8fba80 100644
--- a/src/script.js
+++ b/src/script.js
@@ -1,5 +1,5 @@
 var Opcode = require('./opcode')
-var util = require('./util')
+var crypto = require('./crypto')
 var convert = require('./convert')
 var Address = require('./address')
 var network = require('./network')
@@ -144,10 +144,10 @@ Script.prototype.toScriptHash = function() {
   }
 
   if (outType == 'P2SH') {
-    return util.sha256ripe160(this.buffer)
+    return crypto.hash160(this.buffer)
   }
 
-  return util.sha256ripe160(this.buffer)
+  return crypto.hash160(this.buffer)
 }
 
 //TODO: support testnet
@@ -257,7 +257,7 @@ Script.prototype.simpleInPubKey = function() {
  * This method is useful for indexing transactions.
  */
 Script.prototype.simpleInHash = function() {
-  return util.sha256ripe160(this.simpleInPubKey())
+  return crypto.hash160(this.simpleInPubKey())
 }
 
 /**
diff --git a/src/transaction.js b/src/transaction.js
index 55e9954..0f0bc3f 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -1,11 +1,12 @@
+// FIXME: To all ye that enter here, be weary of Buffers, Arrays and Hex interchanging between the outpoints
+
+var Address = require('./address')
 var BigInteger = require('./jsbn/jsbn')
 var Script = require('./script')
-var util = require('./util')
 var convert = require('./convert')
+var crypto = require('./crypto')
 var ECKey = require('./eckey').ECKey
 var ECDSA = require('./ecdsa')
-var Address = require('./address')
-var SHA256 = require('crypto-js/sha256')
 
 var Transaction = function (doc) {
   if (!(this instanceof Transaction)) { return new Transaction(doc) }
@@ -201,11 +202,9 @@ Transaction.prototype.hashTransactionForSignature =
   }
 
   var buffer = txTmp.serialize()
-
   buffer = buffer.concat(convert.numToBytes(parseInt(hashType), 4))
-  buffer = convert.bytesToWordArray(buffer)
 
-  return convert.wordArrayToBytes(SHA256(SHA256(buffer)))
+  return crypto.hash256(buffer)
 }
 
 /**
@@ -215,8 +214,10 @@ Transaction.prototype.hashTransactionForSignature =
  */
 Transaction.prototype.getHash = function ()
 {
-  var buffer = convert.bytesToWordArray(this.serialize())
-  return convert.wordArrayToBytes(SHA256(SHA256(buffer))).reverse()
+  var buffer = this.serialize()
+  var hash = crypto.hash256(buffer)
+
+  return Array.prototype.slice.call(hash, 0).reverse()
 }
 
 Transaction.prototype.clone = function ()
@@ -300,13 +301,12 @@ Transaction.prototype.sign = function(index, key, type) {
   type = type || SIGHASH_ALL
   key = new ECKey(key)
 
-  // TODO: getPub is slow, sha256ripe160 probably is too.
-  // This could be sped up a lot by providing these as inputs.
-  var pub = key.getPub().toBytes(),
-  hash160 = util.sha256ripe160(pub),
-  script = Script.createOutputScript(new Address(hash160)),
-  hash = this.hashTransactionForSignature(script, index, type),
-  sig = key.sign(hash).concat([type])
+  var pub = key.getPub().toBytes()
+  var hash160 = crypto.hash160(pub)
+  var script = Script.createOutputScript(new Address(hash160))
+  var hash = this.hashTransactionForSignature(script, index, type)
+  var sig = key.sign(hash).concat([type])
+
   this.ins[index].script = Script.createInputScript(sig, pub)
 }
 
diff --git a/src/util.js b/src/util.js
deleted file mode 100644
index 9cbc541..0000000
--- a/src/util.js
+++ /dev/null
@@ -1,13 +0,0 @@
-var convert = require('./convert.js')
-var Crypto = require('crypto-js')
-var RIPEMD160 = Crypto.RIPEMD160
-var SHA256 = Crypto.SHA256
-
-exports.sha256ripe160 = function (data) {
-  var wordArray = RIPEMD160(SHA256(convert.bytesToWordArray(data)))
-  return convert.wordArrayToBytes(wordArray)
-}
-
-exports.error = function (msg) {
-  throw new Error(msg)
-}
diff --git a/test/crypto.js b/test/crypto.js
new file mode 100644
index 0000000..9b2068b
--- /dev/null
+++ b/test/crypto.js
@@ -0,0 +1,49 @@
+var assert = require('assert')
+var crypto = require('../').crypto
+var fixture = require('./fixtures/crypto')
+
+describe('Crypto', function() {
+  describe('HASH160', function() {
+    it('matches the test vector', function() {
+      fixture.before.hex.forEach(function(hex, i) {
+        var actual = crypto.hash160(new Buffer(hex, 'hex')).toString('hex')
+        var expected = fixture.after.hash160[i]
+
+        assert.equal(actual, expected)
+      })
+    })
+  })
+
+  describe('HASH256', function() {
+    it('matches the test vector', function() {
+      fixture.before.hex.forEach(function(hex, i) {
+        var actual = crypto.hash256(new Buffer(hex, 'hex')).toString('hex')
+        var expected = fixture.after.hash256[i]
+
+        assert.equal(actual, expected)
+      })
+    })
+  })
+
+  describe('SHA1', function() {
+    it('matches the test vector', function() {
+      fixture.before.hex.forEach(function(hex, i) {
+        var actual = crypto.sha1(new Buffer(hex, 'hex')).toString('hex')
+        var expected = fixture.after.sha1[i]
+
+        assert.equal(actual, expected)
+      })
+    })
+  })
+
+  describe('SHA256', function() {
+    it('matches the test vector', function() {
+      fixture.before.hex.forEach(function(hex, i) {
+        var actual = crypto.sha256(new Buffer(hex, 'hex')).toString('hex')
+        var expected = fixture.after.sha256[i]
+
+        assert.equal(actual, expected)
+      })
+    })
+  })
+})
diff --git a/test/fixtures/crypto.js b/test/fixtures/crypto.js
new file mode 100644
index 0000000..790fa9e
--- /dev/null
+++ b/test/fixtures/crypto.js
@@ -0,0 +1,37 @@
+module.exports = {
+  before: {
+    hex: [
+      '0000000000000001',
+      '0101010101010101',
+      'FFFFFFFFFFFFFFFF',
+      '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'
+    ],
+  },
+
+  after: {
+    hash160: [
+      'cdb00698f02afd929ffabea308340fa99ac2afa8',
+      'abaf1119f83e384210fe8e222eac76e2f0da39dc',
+      'f86221f5a1fca059a865c0b7d374dfa9d5f3aeb4',
+      '9763e6b367c363bd6b88a7b361c98e6beee243a5'
+    ],
+    hash256: [
+      '3ae5c198d17634e79059c2cd735491553d22c4e09d1d9fea3ecf214565df2284',
+      '728338d99f356175c4945ef5cccfa61b7b56143cbbf426ddd0e0fc7cfe8c3c23',
+      '752adad0a7b9ceca853768aebb6965eca126a62965f698a0c1bc43d83db632ad',
+      '033588797115feb3545052670cac2a46584ab3cb460de63756ee0275e66b5799'
+    ],
+    sha1: [
+      'cb473678976f425d6ec1339838f11011007ad27d',
+      'c0357a32ed1f6a03be92dd094476f7f1a2e214ec',
+      'be673e8a56eaa9d8c1d35064866701c11ef8e089',
+      '10d96fb43aca84e342206887bbeed3065d4e4344'
+    ],
+    sha256: [
+      'cd2662154e6d76b2b2b92e70c0cac3ccf534f9b74eb5b89819ec509083d00a50',
+      '04abc8821a06e5a30937967d11ad10221cb5ac3b5273e434f1284ee87129a061',
+      '12a3ae445661ce5dee78d0650d33362dec29c4f82af05e7e57fb595bbbacf0ca',
+      'a7fb8276035057ed6479c5f2305a96da100ac43f0ac10f277e5ab8c5457429da'
+    ]
+  }
+}
diff --git a/test/misc.js b/test/misc.js
index e02c924..121f479 100644
--- a/test/misc.js
+++ b/test/misc.js
@@ -1,17 +1,13 @@
 var assert = require('assert')
 var bitcoinjs = require('../')
+var crypto = require('../').crypto
 var sec = require('../src/jsbn/sec')
 var BigInteger = require('../src/jsbn/jsbn.js')
-var SHA256 = require('crypto-js/sha256')
 var rng = require('secure-random')
 var ecparams = sec('secp256k1')
 var ECPointFp = bitcoinjs.ECPointFp
 var convert = require('../src/convert')
 
-function sha256FromBytesToBytes(message){
-  return convert.wordArrayToBytes(SHA256(convert.bytesToWordArray(message)))
-}
-
 it('Keys & Key Management', function () {
   var p1 = bitcoinjs.Key().getPub().toBytes()
   assert.equal(p1.length, 65)
@@ -37,7 +33,7 @@ it('Signing and Verifying', function () {
   assert.ok(s1.verify(BigInteger.ZERO, sig_a))
 
   var message = new BigInteger(1024, rng).toByteArrayUnsigned()
-  var hash = sha256FromBytesToBytes(message)
+  var hash = crypto.sha256(message)
   var sig_b = s1.sign(hash)
   assert.ok(sig_b, 'Sign random string')
   assert.ok(s1.verify(hash, sig_b))
@@ -49,7 +45,7 @@ it('Signing and Verifying', function () {
     '8a33f50d7cefb96a5dab897b5efcb99cbafb0d777cb83fc9b2115b69c0fa' +
     '3d82507b932b84e4')
 
-  var hash2 = sha256FromBytesToBytes(message2)
+  var hash2 = crypto.sha256(message2)
 
   var sig_c = bitcoinjs.convert.hexToBytes(
     '3044022038d9b8dd5c9fbf330565c1f51d72a59ba869aeb2c2001be959d3' +
diff --git a/test/script.js b/test/script.js
index b6ce5e9..6a611ac 100644
--- a/test/script.js
+++ b/test/script.js
@@ -2,8 +2,7 @@ var Script = require('../src/script.js')
 var assert = require('assert')
 var Address = require('../src/address.js')
 var Network = require('../src/network.js')
-var Util = require('../src/util.js')
-var sha256ripe160 = Util.sha256ripe160
+var crypto = require('../').crypto
 var Convert = require('../src/convert.js')
 var bytesToHex = Convert.bytesToHex
 var hexToBytes = Convert.hexToBytes
@@ -83,7 +82,7 @@ describe('Script', function() {
 
     it('should create valid multi-sig address', function() {
       script = Script.createMultiSigOutputScript(numSigs, compressedPubKeys.map(hexToBytes))
-      multisig = sha256ripe160(script.buffer)
+      multisig = crypto.hash160(script.buffer)
       var multiSigAddress = Address(multisig, network).toString()
 
       assert.ok(Address.validate(multiSigAddress))
@@ -107,7 +106,7 @@ describe('Script', function() {
       assert.equal(sigs[0], '02ea1297665dd733d444f31ec2581020004892cdaaf3dd6c0107c615afb839785f')
       assert.equal(sigs[1], '02fab2dea1458990793f56f42e4a47dbf35a12a351f26fa5d7e0cc7447eaafa21f')
       assert.equal(sigs[2], '036c6802ce7e8113723dd92cdb852e492ebb157a871ca532c3cb9ed08248ff0e19')
-      assert.equal(Address(sha256ripe160(redeemScript), network).toString(), '32vYjxBb7pHJJyXgNk8UoK3BdRDxBzny2v')
+      assert.equal(Address(crypto.hash160(redeemScript), network).toString(), '32vYjxBb7pHJJyXgNk8UoK3BdRDxBzny2v')
     })
   })
 })
diff --git a/test/wallet.js b/test/wallet.js
index d69674e..a998286 100644
--- a/test/wallet.js
+++ b/test/wallet.js
@@ -7,8 +7,7 @@ var Script = require('../src/script.js')
 var convert = require('../src/convert.js')
 var assert = require('assert')
 var sinon = require('sinon')
-var SHA256 = require('crypto-js/sha256')
-var Crypto = require('crypto-js')
+var crypto = require('../').crypto
 
 var fixtureTxes = require('./fixtures/mainnet_tx')
 var fixtureTx1Hex = fixtureTxes.prevTx
@@ -17,7 +16,7 @@ var fixtureTx2Hex = fixtureTxes.tx
 describe('Wallet', function() {
   var seed, wallet
   beforeEach(function(){
-    seed = convert.wordArrayToBytes(SHA256("don't use a string seed like this in real life"))
+    seed = crypto.sha256("don't use a string seed like this in real life")
     wallet = new Wallet(seed)
   })